Minerals: magnetite and hematite (low grade iron-ore)
Type of Mine: open-pits; Tilden is 2 miles long by 1/2 mile wide and Empire is 1 mile across and 1,200 feet deep.

Production life: Empire has been in operation since the 1964 and shut down in August 2016 (remediation has not yet started). Tilden has operated since 1989 and may continue operations for another 30 years.

Impacts and Concerns:

Scale of land alteration - over hundreds of square miles of permanent mine pits and waste storage sites

Status: In-operation. On January 15, 2013, the U.S. Environmental Protection Agency issued a Federal Implementation Plan to set air pollution standards for the Tilden Mine along with five other taconite facilities in Minnesota.